Blood Prodigy
by WhiteAsukalover
Summary: AU Sequel to Blood Marionette! After killing Toph while under the Dai Li's control, Aang and Sokka abandon Katara, leaving her alone and in tears, a broken soul. Azula finds her and takes her in as her sister but the damage is done to Katara's psyche and she slowly goes insane... Hints of TyZula, Azutara and KaToph. Official pairing will come later. Written with RosenKruz!
1. Broken Soul

_A/N: Hey guys, White here with a special AU sequel to Blood Marionette. It is a dark alternate ending story to its predecessor which explores what would've happened had Katara actually killed Toph in Blood Marionette. Hope y'all enjoy it!_

_Previously In Blood Marionette_

_"Katara stop," Aang pleaded. "Look, you can take me to Azula. I won't even escape when she has me. Just let the others go, please!"_

_"I know you won't escape. You'll be an Avatar-sicle." She sneered._

_"Fine," Aang replied. "If I surrender, what happens to the others? Will you let them go free?" Aang pleaded. At this point, he just wanted his friends to be safe._

_"I was instructed to kill, that's what I'll do even if you come with me." Katara replied, her tone extremely chilly._

_"Sugar Queen, please," Toph pleaded. "You don't have the heart to kill," she challenged bravely._

_"Oh don't I? Watch me. I'll kill you first, which should be simple because you can't see. I'll make all of you watch the rest of you die, and your up first." She sneered at Toph._

_"And how to you propose to kill all of us?" Toph demanded._

_"Like this." She purred silkily, and started bloodbending her blind target, cackling._

_Toph's bravado began to fade as she felt the pain. "You don't need to do this!" Aang screamed. "You can have me. I'll come quietly. But let the rest of our friends go!" He begged._

_"I told you Avatar, I was meant to kill..." She answered, before much to her shock, her grip on Toph began to fade, as the blind bender was using every bit of her will to break the hold._

_"Sugar Queen, this isn't you," Toph gurgled._

_"Or maybe Sokka should be first," she threatened. "I wouldn't want you to miss that." She teased, smiling cruelly._

_"You wouldn't...he might be an idiot at times but he's your brother.." Toph pleaded._

_"And we're back to the blind bimbo," Katara said, focusing. She had come up with a most exquisite torture._

_"It's blind bandit, Sugar Queen. Get it right." Toph growled. Even in her weakened state, her pride was still very much in tact._

_Katara said nothing. She continued to focus. "Do you feel it yet?" she asked._

_Toph groaned as her bravado faded instantly. "My...feet, their so numb..I can't feel them...and everything's dark...I can't see anything."_

_Katara's face wore a predatory smile. She flashed her teeth to her audience. "Would you like to know why?" she asked gleefully._

_"Not particularly, but your gonna tell us anyway aren't you?" Sokka deadpanned._

_"Yes, since your dying to know. Blind Bimbo, what I am doing, is slowly stopping the flow of blood throughout your body. That feeling of numbness you're experiencing is only gonna get worse. See, I'm starting with your feet. But soon, I'll move up to your legs, then your arms, before finally making your poor little heart shut down. You'll be aware the entire time, but you'll be helpless to do anything but wait for the end. Wait, you're blind now, so you're used to being helpless," Katara gloated._

_Toph's eyes had a figurative fire burning in them._

_"Ahh, so fierce," Katara gloated. "Soon the fire in your eyes, that fire's gonna burn out." She giggled maliciously._

_"No..no...if you have to kill me, end it quick Sugar Queen. If you have a heart, make it quick.." Toph begged._

_"Where's the fun in that?" Katara asked. "Shh, it'll be over soon. Hush now." Katara taunted._

_"No...I'll never give in." Toph moaned in pain._

_"You will," Katara replied. "Mistress Azula would approve of me using the most torturous way possible to kill her enemies," she bragged, increasing her hold._

_For the first time in her life, Toph looked legitimately scared. Her eyes quivered as they radiated fear as the numbness spread up her legs. "Katara...please...stop."_

_"So ends the Blind Bimbo," Katara gloated, stopping the flow of blood to Toph's waist. "And so young. Tell me, what would you like your gravestone to say?" she asked cruelly._

_Toph looked at her, her spirit just about broken. "Gravestone?" She asked. _

_"Katara please...this isn't you. Remember who you really are." Aang pleaded._

_"Look at it this way," Katara said. "I'm putting you out of your misery. Now, let's see a brave face," she coached._

_Present Time_

"K...Katara...I...I can't breathe real well...please...stop!" Toph begged, tears in her eyes.

Katara, ignoring the pleas of her former friend, clenched her hands into tight fists. "Mistress Azula will be very pleased to see you, Avatar. But first, I'm going to enjoy turning the blind bimbo here into a lifeless husk!" She sneered, cackling.

Toph let out a weak scream of agony. "Kat...ara...please...stop...we...l...ove you...I...cant take much more..." She gasped out.

"Hmph... by now your arms should be pretty useless. Now for the heart. Let's see you squirm!" Katara laughed in a sickeningly evil way as she continued to crush Toph's body from the inside.

Toph's eyes shut as she gritted her teeth in pain, mentally screaming. She'd never felt such pain in her short life.

Katara gave a simple, but very evil smile as she watched her handiwork. "And now, for the finale. Goodbye, Blind Bimbo. And good riddance!"

With that, Katara gave a swift flick of the wrist, forcing the blood out of Toph's heart.

Right as her last breath was about to leave her, Toph gave one final cry to her. "Katara...save...yourself.." She murmured, before her body turned cold and lifeless, as she collasped, gone...

At that moment, Katara's eyes widened as the Dai Li's grip was broken, and she looked down at Toph's lifeless body. What she saw was horrifying.

"I... I did... Wh..what have I done?!" was all she could choke out between immediate tears of grief and regret.

"K...Katara, how...how could you do this to her? Toph looked up to you! She saw you as a big sister!" Sokka cried out in anguish.

"I di...didn't want to... I couldn't control myself... Please... please help me..." Katara began to beg as she cried, crawlling towards Toph's cold, lifeless body.

"**STAY AWAY FROM HER!** Haven't you done enough, Katara?!" Aang yelled as he finally managed to find his voice, and he began to scowl at the monster the young bloodbender had become.

"I expected something like this out of Ozai, or maybe even Zuko, but not you, Katara! Never you! You... **YOU'RE A MONSTER!**" Aang screamed in anguish

Katara's eyes filled with tears. "A...Aang, that wasn't me...you know I'd never hurt anyone. I'm not a killer." She whimpered.

Sokka turned his back to Katara, his voice low, and cold. "You're not my sister. You're just a monster wearing her face. The Katara I knew would never let anyone control her!"

All Sokka could do was run away from the scene with tears in his eyes, not wanting to watch his baby sister destroy herself anymore.

"Sokka...come back...come back." Katara whimpered.

Aang slowly walked towards her, seemingly to comfort her. Katara's eyes begun to fill with hope once again, until it was shattered as the young Avatar picked up his deceased comrade, and turned to walk away.

"Sokka's right Katara... you're a monster. Goodbye... forever..." were Aang's final words to Katara as he followed after Sokka. His eyes were not the same anymore. Now, they were full of heartbreak.

"Aang, no please!" Katara begged.

Katara rolled over onto her other side as they walk away, only to see Azula standing before her. The Fire Nation princess leaned down to Katara's ear level, and began whispering into her ear.

"Well, well, well, it seems I was right. I knew they'd betray you, Katara. They just don't understand the 'real' you... unlike me." She cooed softly.

"Azula..." Katara murmured softly.

"They just don't understand you... they fear you... they hate you... but I don't. I understand you. Your true desires." Azula giggled as she kept whispering into Katara's ear, filling the broken waterbenders head with her voice.

"They hate me...you understand me...my true desires..." Katara murmured.

Azula placed her hands around Katara's waist, raising her up into a hug, resting her head on the Bloodbenders shoulder. "I can give you what you truly want... what you really desire... I can help you get your revenge against those that betrayed you, my little waterbender." She purred wickedly.

"You can Azula?" Katara asked.

Azula's lips curled up into a devious smile. She had finally broken her completely. "Of course. You poor, sweet girl. Your friends have abandoned you... but I will never leave you."

"Of course..." Katara answered softly.

"Come on now... we can't have you crying over that Earthbender like that. She would probably have betrayed you as well..." Azula whispered in her ear.

"But...I killed her." Katara whimpered.

"Yes... but you did it so that she could not kill you first. They feared you... they wanted to get rid of you..." Azula chuckled softly.

"They did?" Katara asked quietly.

Azula gently pulled Katara into another friendly embrace, speaking to her softly and kindly. "Why would I lie to my favorite girl?"

"I'm your favorite girl?" Katara asked, surprised.

"I've never held Mai or Ty Lee like this... you're mine, and I intend to keep it that way." Azula's devious grin curled into a sincere smile for a moment, before her cunning mind began racing again.

Katara nuzzled into her embrace, hugging her tight.

The Firebending princess helped Katara to her feet, smiling at her all the time. "Come along now... let's get you into something a little more... flattering." She smirked.

"Of course Azula...I'm yours now.." Katara murmured softly.

Azula took her newest acquisition by the hand, leading her through the streets of Ba Sing Se with victorious pleasure. She had succeeded in breaking the Avatar's will, and gained a new ally all at once.

Katara looked up at Azula. Her once bright blue eyes were now a dark icy shade.

As soon as Azula and Katara had arrived at the Princess's "Home away from Home", Mai and Ty Lee spotted the Waterbender, and immediately sprung into offensive stances.

"What is **SHE** doing here, Azula?!" Mai questioned, a little confused.

Katara clung to her, nervous.

"Katara is on our side now, Mai. Now, put the knives down... you're scaring her." Azula commanded with seemingly divine authority, causing the bubbly Ty Lee to calm down and skip over to Katara happily.

"Ya know, now that I get a good look at you... you're actually kinda cute lookin'." The smiley Chi-Blocker could only gaze at Katara's scared and confused expression happily, taking in every detail of the waterbenders face.

Katara eased up. "You think so?" She asked innocently.

"Definitely. Your skin reminds me of chocolate... and your hair is so shiny... it's beautiful..." Ty Lee continued to admire Katara's appearance, much to the irritation of a now jealous firebender.

"I like both of you...Azula...Ty Lee.." Katara admitted.

Azula cleared her throat for a second, grabbing the always-happy gymnasts attention. "Ty Lee, could you take Katara to find something more suitable to wear? I'd think she's dying to get out of those trashy peasant rags!"

"Right away Azu!" Ty Lee squealed happily.

Ty Lee took Katara by the hand and practically dragged her to a large wardrobe filled with clothes.

Azula, on the other hand, sat down and smiled. "So Mai... anything you'd like to say?"

"About what?" Mai drawled.

"About our newest arrival. Katara's a former companion of the Avatar. Don't you have an opinion about that?!" Azula was actually curious, and a little confused by how well Mai was taking this turn of events.

"I knew she'd snap eventually." Mai chuckled dryly.

Azula opened her mouth to reply, but found the words lost in her throat as Katara came back into the room, wearing a small red tank top, a red skirt, and some red sandals

"H...how do I look?" was all Katara was able to say, as she blushed a bright red color.

"Perfect!" Ty Lee squealed.

"Wow... j..just wow... You know, for a Water Tribe peasant, you certainly look the part of Fire Nation nobility when you try." Azula replied, unaware of the bright red tint on her cheeks.

"Oooooh, your blushing Azula!" Ty Lee giggled.

Azula turned her head away from Ty Lee, trying to hide her obvious blush. "I am not... it's...just quite warm in here..."

Katara skipped to Azula's side, beaming.

"So Katara... I've been wondering... what was that thing you did to that blind earthbending ex-friend of yours?" the Firebending Princess asked with avid curiousity.

"Bloodbending." Katara answered.

"Never heard of it. What's it do?" Mai interrupted, completely uninterested in the conversation, but engaging anyways.

"It manipulates the blood in one's body." Katara answered.

"Wait, what? How is that possible? I didn't think Waterbending could manipulate anything except... well... Water." Mai's sudden interest in the conversation did not go unnoticed by the others, but they didn't seem to mind.

Katara was slowly breaking her out of her shell of indifference, which was a feat unto itself.

"Think about it. Blood in its simplest form is water.." Katara explained, feeling a smirk creep on to her face.

Mai actually started becoming more interested in the conversation as it went on, asking as many questions as she could.

"So, where did you even learn to do all of that in the first place? Ya know, the whole Bloodbending thing...?" She asked.

"I was taught by someone." Katara replied plainly.

At that point, Ty Lee decided to butt in. "Boooooorrrrrrriiiiiiiing! Come on, let's talk about something else. Like that cute Water Tribe guy you were with." The bubbly chi-blocker giggled a little as Katara's expression turned to one of annoyance at the mention of her ex-Brother.

Katara turned away, still visibly hurting from Sokka's betrayal. She couldn't believe he'd turn his back on his own sister..

"Oh, enough Ty Lee. Can't you see the poor girl is still feeling the sting of betrayal? Her own brother turned his back on her after what the Dai Li made her do to their Blind Earthbender..." Azula interrupted, in a practiced tone of sympathy.

Katara's eyes filled with tears. It was the lowest point of her life..

Azula stood up from her seat, and began walking up to the crying Bloodbender from behind, wrapping her arms around her neck in a light embrace. "You know, I have a truly perfect way to get back at those traitors for hurting you."

"What is it Azula...I just feel so hurt..so alone. I have no one anymore...I was in love with Aang...and...and he thinks I'm a monster!" Katara wailed in anguish.

Hearing her cries of pain and torture, the Fire Nation Princess gave Katara a gentle squeeze, seeming to show genuine concern for her waterbending accomplice. "Well... why not be my new Sister. Zu-Zu would probably call em crazy for this, but I want to make you feel happy. So, Katara, want to be my little Sister?"

Mai and Ty Lee were in utter shock, their mouths open wide, and both speechless.

"Be your sister?" Katara murmured softly.

"That's right Katara. I'm the Princess of the Fire Nation. I can have anything I want, whenever I want it. And yet, here I am, letting you choose to be mine... Just think about it, ok?" Azula gave one of her trademark "Daddy's girl" smiles, before standing up to walk out of the room.

"Wait...dont leave me Azula." Katara whispered. She clearly needed the devious princess.

"Don't worry. I'm not going to leave. I just want to go and practice something..." the Princess mused as she raised 2 of her fingers into the air slightly, having them spark with electrical energy as she did.

Katara nodded shakily.

Azula smiled as she walks out of the room, leaving her waterbender to change from outspoken, bubbly teenager to broken, lonely child almost instantly.

Katara pulled her knees in close to her body and began to rock in place crying. She was a horribly broken soul.

Ty Lee looked over to the frightened water tribe girl, then at Mai, confused by what she just saw. "Ok... what just happened?"

The 2 Non-Benders suddenly turned their attention towards their newest accomplice, and immediately realized that there was something wrong with her.

Katara was on her side, curled up in a ball, and crying. All she kept doing was repeating the words "I'm so sorry... please don't leave me..." over and over again.

Ty Lee realized this and hugged her gently, rocking her. "Shhh...its okay.."

"P..please... help me... A...A..." Katara's cries grew slowly louder as she choked on what seemed to be a name.

"Shhh...it's okay Katara. You don't need the Avatar. Mai, me and Azula, we're your friends now." The bubbly chi-blocker cooed.

The broken waterbender continued to cry as Ty Lee attempted to comfort her. Her spirit was completely broken, and she was finally coming to terms with what had happened.

"P..please... make it stop... no more pain... please... help me... A...zula..." She sobbed miserably.

To be continued...


	2. Psycho Unleashed

_Last Time On Blood Prodigy_

_Katara pulled her knees in close to her body and began to rock in place crying. _

_Ty Lee looked over to the frightened water tribe girl, then at Mai, confused by what she just saw. "Ok... what just happened?"_

_The 2 Non-Benders suddenly turned their attention towards their newest accomplice, and immediately realised that there was something wrong with her._

_Katara was on her side, curled up in a ball, and crying. All she kept doing was repeating the words "I'm so sorry... please don't leave me..." over and over again._

_Ty Lee realized this and hugged her gently, rocking her. "Shhh...its okay.."_

_"P..please... help me... A...A..." Katara's cries grew slowly louder as she choked on what seemed to be a name._

_"Shhh...it's okay Katara. You dont need the Avatar. Mai, me and Azula, we're your friends now." The bubbly chi-blocker cooed._

_The broken waterbender continued to cry as Ty Lee attempted to comfort her. Her spirit was completely broken, and she was finally coming to terms with what had happened._

_"P..please... make it stop... no more pain... please... help me... A...zula..." She sobbed miserably._

_End Flashback_

Ty Lee's ears perked up at Azula's name. "Azula!" She called.

The now irritated Fire Nation Princess walked back into the room in a small temper. "What is so important that you have to distract me from my training, Ty Lee?"

"It's Katara, she was calling for you." Ty answered sympathetically.

Azula's mouth curled into her classic devious smirk as she walked over to the crying waterbender. "Katara? Are you alright?"

"Azula! Sister, help me!" Katara squealed in fright and pain, as she clung to her like a life perserver.

Azula's eyes widened at the action. "D...did you really... just call me 'Sister'?" She asked in disbelief.

Katara nodded, shaking as she sobbed.

"It's ok...No one's going to hurt you anymore. No one is going to come between us, I promise." Azula wrapped her arms around Katara's body, holding her in a protective embrace.

Katara hugged her as tight as possible. "Don't go...don't go...don't goooo!" She wailed.

"I'm not going anywhere. I'll never abandon you." Azula whispered into her ear mischievously.

"Never abandon me...please..." Katara whispered.

Ty Lee just giggled at the relationship between the 2 opposites.

"Katara... are you going to be ok now?" Azula gently pulled herself away from the waterbender for a moment.

"I...I need..." She murmured softly.

Azula stared at her, curious as to what she wanted to say. "What do you need, sister?"

"**REVENGE!**" Katara screamed, cackling psychotically.

Azula's eyes widened as her smirk turned into a full blown grin. "At last. Finally decided to let your true self come out, sister?"

Katara grinned sadistically, pulling her hair into pigtails, her eyes full of crazed and bloodshot rage as she giggled.

"Well then... shall we go and find the monsters that betrayed you, my sweet little sister?" The Firebender laughed sadistically, admiring how evil Katara now looked.

"Yes...yes...so I can destroy them!" Katara cackled sadistically.

Both of the non-benders in the room shared a glance that screamed 'Oh god, not another Azula!'

Katara looked to them and switched to her sweet persona, blowing them a kiss.

Ty Lee smiled nervously at her, waving a hello her way, and forcing herself to giggle.

Azula turned her head towards Mai and Ty Lee, mirroring Katara's sweet, innocent look. "Oh relax you two. Katara would never hurt either of you, right?"

"That's right. You guys are my friends, I care about you." Katara replied, genuinely sweet.

"Oh... Okey dokey then." was Ty Lee's response, her fear instantly replaced by her usually giggly-ness

Katara smiled wide, hugging Ty Lee, giggling just like her.

Azula snapped her fingers, and 3 Dai Li agents enter the room. "Sister dearest... why don't you work out your frustrations on these 3 insignificant Earth Kingdom peasants, while I go and fetch you something that will truly make you smile."

Katara smiled gleefully, as she happily began to bloodbend them.

Mai cracked a smile as she saw how remorseless Katara was with her Bloodbending abilities. _'I may just like her after all.'_ She thought.

Katara grinned sadistically, stopping the flow of blood in their bodies simultaneously. Within minutes, all 3 dropped dead..

Azula came back in after a few minutes, holding a small decorative chest. "Katara. I found it. Want to see it now?" She purred.

Katara squealed, jumping up and down. "Yes, yes! Show me!"

"Ok, but only because my dear sister asked so nicely." Azula smiled as she opened the chest, revealing a crown similar to the one Azula herself had, only this one was silver and encrusted with sapphires.

"I have no idea where I got this thing, but now it just makes me think of my darling waterbender..." She cooed.

Katara's eyes filled with happy tears. "Sister...you got this for me?"

The Firebender's smirk curled into a genuinely sweet smile, and she put on an innocent face. "Of course. A Princess is nothing without her crown, after all." She giggled.

"Oh Azula...I love you..." Katara murmured.

Azula's face looked stunned. "I...I don't know what to say...except..." Azula pulled Katara into a tight hug, smiling happily "I love you too Katara..." She beamed lovingly.

"I love you too Azula. More than anyone, even Aang.."

Ty Lee finally decided to interrupt their adorable moment of sisterly bonding. "Ok, now that that's done... I heard there was a new Tea Shop open in the Upper Ring. Anyone wanna go check it out?"

"You mean the 'Jasmine Dragon? Yes, I had heard about that. It sounds like the perfect way to celebrate the newest addition to our little family." Azula grinned happily, holding Katara by the hip.

"I love you Azula, my beautiful perfect sister.." Katara cooed dreamily.

"Well, you're right about that. I am perfect, but YOU'RE the beautiful one." The firebender replied affectionately.

"Awww...Azu..." Katara blushed. She was completely wrapped around Azula's finger. Azula pulled all her strings.

"Well... let's go then... no sister of mine is going to celebrate by herself." Azula simply grinned and took Katara by the arm, leading her out of the large building

Katara sighed dreamily, clearly in love.

A short time later, the group of 4 arrived at the new Jasmine Dragon.

"Well... this is the place. I must say, it looks awfully welcoming... almost like it would fit into a Fire Nation village..." Azula mused as she was in awe at how much the building reminded her of home.

"Home.." Katara murmured longingly.

"That's right, Sister. No more South Pole for you. The Fire Nation's Capitol City, Caldera, is your new home." Azula cooed into her ear quietly, playfully teasing her about her new found loyalties. "Now come along. I'm anxious to see the service they provide."

"Yes sister.." Katara murmured emotionlessly, like she was programmed..

The four Red-clad teens enter the beautiful tea shop, and the first thing Katara does is nervously hide behind Azula, almost like she's seen a ghost.

"K..Katara? What's the matter?" Azula asked gently.

"Zuko..." She squeaked.

Just then, said exiled Prince turned to greet his new customers, only to recieve 2 huge surprises.

"Greetings. Welcome to the Jas-Azula?! A..and is that Katara?! Why are you here... and why are you... together?!" He yelled in surprise.

To be continued...


End file.
